Various methods for extracorporeal blood treatment are known. In an extracorporeal blood treatment, the patient's blood is cleaned in an extracorporeal blood circuit, which comprises a replacement unit, for example a dialyser or filter. The dialyser or filter comprises a blood chamber and a dialysing fluid chamber, which are separated by a semipermeable membrane. In haemodialysis in the narrower sense, blood flows through the blood chamber of the dialyser and dialysing fluid flows through the dialysing fluid chamber. In haemofiltration, the fluid withdrawn from the patient via the semipermeable membrane of the dialyser or filter is completely or partially replaced by a sterile substitution fluid (substituate), this being possible either upstream or downstream of the dialyser. Haemodialysis and haemofiltration can also be combined into one assembly, which is referred to as haemodiafiltration. These variants are referred to in the following as haemodialysis in the broader sense.
Apart from haemodialysis, peritoneal dialysis is also known, in which a peritoneal solution is fed to the patient's peritoneal space and is carried away from the peritoneal space via an implanted peritoneal catheter. In peritoneal dialysis, the blood treatment takes place through the peritoneal space.
In haemodialysis, the dialysis fluid can be made available with a central supply unit. The substituate can be obtained from fresh water and concentrate or from the dialysing fluid. In the case of acute haemodialysis, it is known to use dialysing fluid and substituate which is made available in bags. In order to make available dialysing fluid and substituate, multi-chamber bags are also known, which are filled with various constituents for the preparation of the dialysing fluid or the substituate. The individual constituents are usually mixed together for the preparation of the ready fluid only shortly before the treatment.
Known solution bags for the preparation of dialysing or substitution fluid comprise two separate chambers, whereof one chamber is filled with bicarbonate as an alkaline solution and the other chamber with an acid solution of calcium and electrolyte. The two chambers of the double-chamber bag enclosed by an outer packaging are separated by a separable seam. After removal of the bag from the outer packaging and separation of the seam, the two solutions are mixed to form a pH-value neutral dialysing or substitution fluid with an approximately physiological pH value. Depending on the embodiment, there is integrated in the primary packaging and/or the outer packaging a gas barrier which prevents outgassing of CO2 from the bicarbonate solution and a resultant shift in the ph value to higher values. As a result of inappropriate storage and handling, however, damage to the packaging may occur, so that the pH value of the bicarbonate solution is shifted to higher values. In such a solution, precipitation of calcium carbonate in the ready dialysing or substitution fluid can occur as a solid constituent. The infusion of these particles then represents a threat to the patient.
The problem of the infusion of precipitating solid constituents also arises with peritoneal dialysis, in which the peritoneal solution is made available in a multi-chamber bag, which contains the constituents to be mixed together only shortly before the treatment. The peritoneal solution differs from the dialysing fluid essentially through the glucose content. Here too, inappropriate storage of or damage to the packaging can lead to precipitation of calcium carbonate as solid constituents, which may get into the patient's peritoneal space. Other undissolved substances or parts, for example splinters of break-off cones, may also be contained in the peritoneal solution.
The known blood treatment apparatuses comprise hose lines which are intended for one-off use. Such hose lines are offered as sets. The hose lines are inserted into occluding pumps, in particular roller pumps. Occluding pumps are also understood in the following to mean pump systems comprising a non-occluding pump, for example a centrifugal pump, with upstream and/or downstream valves, which are triggered by a control in such a way that the system of valve or valves and non-occluding pump behaves like an occluding pump.
Balancing devices are known in blood treatment for balancing fresh against consumed dialysing fluid. Balancing devices are known in which the bags, in which the fresh dialysing fluid is made available and the consumed dialysing fluid is received, are weighed. These balancing devices therefore comprise balances for the solution bags.
U.S. Pat. No. 5,605,545 describes a medical arrangement with bags for accommodating fluids, to which a hose line is connected which leads to a surgical instrument. The fluids from the bags are conveyed by an occluding hose pump. The hose set also comprises a bypass line, which bridges the hose section of the hose line inserted into the pump. Located in the bypass line is a non-return valve, which limits the pressure in the hose set to a specific level. An infusion line with a bypass line for pressure limitation is also known from U.S. Pat. No. 4,391,599.
A problem addressed by the present invention is to provide a hose set for an apparatus for blood treatment, in particular an extracorporeal blood treatment apparatus or an apparatus for peritoneal dialysis, which permits an operation of the blood treatment apparatus that is safe for the patient. Moreover, a problem addressed by the present invention is to provide a blood treatment apparatus, in particular an extracorporeal blood treatment apparatus or an apparatus for peritoneal dialysis, which offers increased safety for the patient.